Following the conclusion of the Great Sith War, a significant conflict unfolded on the world of Thule. In this engagement, the forces of the Galactic Republic, aided by the ex-Sith Lord known as Ulic Qel-Droma, successfully neutralized the Dark Reaper, a formidable Sith superweapon.
The New Essential Chronology states that the Dark Reaper was unleashed upon Raxus Prime, and its eventual destruction also took place on that very planet.